Home
SearchSearch MemberlistMemberlist RegisterRegister ProfileProfile Log in to check your private messagesLog in to check your private messages Log inLog in

What's the latest lens you added to your collection?
View previous topic :: View next topic  


PostPosted: Wed Aug 07, 2019 6:41 pm    Post subject: Reply with quote

The first time ever I saw this one here in Switzerland - not exactly a common lens, though it was not that expensive when new.
This Yashica ML 5.6/300mm C looks and feels "like new": no dents. no scratchings, and smooth focusing. A real joy to play with ...!


Compared to contemporary 5.6/300mm lenses such as the Canon nFD 5.6/300mm IF or the Minolta MD 5.6/300mm, the Yashica is a bit inferior: Less resolution in the field and in the corners, and bit more CAs. The Yashica is, however, the shortest of the three lenses mentioned, and therefore aberrations are more difficult to correct:


Stephan


PostPosted: Wed Aug 07, 2019 7:36 pm    Post subject: Reply with quote

stevemark wrote:
... shortest of the three lenses mentioned, and therefore aberrations are more difficult to correct
...


because necessary angles of correction are steeper? Optical materials and techniques such as apo and aspherical also contribute or lessen length imho.


PostPosted: Wed Aug 07, 2019 7:51 pm    Post subject: Reply with quote

So the Exakta mount silver CZJ 135mm f4 Sonnar arrived in the post. Impressed with it so far. . Below are generally unprocessed other than a bit of colour temp shift and upping the exposure a touch if needed. Iso 100, sony a6000











PostPosted: Wed Aug 07, 2019 8:08 pm    Post subject: Reply with quote

Congrats

Nice samples!
I have the same lens and it performs well, but is hard to focus because of stiffness so
I bought a black one for M42.


PostPosted: Thu Aug 08, 2019 9:54 am    Post subject: Reply with quote

uddhava wrote:
Congrats

Nice samples!
I have the same lens and it performs well, but is hard to focus because of stiffness so
I bought a black one for M42.


Yes, I agree - nice samples.
I expect that you will get the most from this lens as you use it more
Tom


PostPosted: Thu Aug 08, 2019 10:03 am    Post subject: Reply with quote

Page 100 of 100 Exclamation


PostPosted: Thu Aug 08, 2019 10:11 am    Post subject: Reply with quote

visualopsins wrote:
Page 100 of 100 Exclamation


That is more than 25 pages per year.
A very popular thread
Tom


PostPosted: Thu Aug 08, 2019 5:35 pm    Post subject: Reply with quote

Wow, 100 pages! I think I want to check in.



Went eBay fishing and caught mint Minolta MD 135mm F3.5:




And I've recently got Minolta MC Rokkor-PF 55mm F1.9




I've shot one with the other and vice versa for the kicks.


PostPosted: Fri Aug 09, 2019 9:17 am    Post subject: Reply with quote

Well here's today's post...



Quite impressed so far..



Unprocessed other than the exposure upped about half a stop..


PostPosted: Fri Aug 09, 2019 7:39 pm    Post subject: Reply with quote

visualopsins wrote:
stevemark wrote:
... shortest of the three lenses mentioned, and therefore aberrations are more difficult to correct
...


because necessary angles of correction are steeper?


Yes. If we look at the common construction of 200mm and 300mm lenses around 1980, we can find a triplet typ "master lens" (positive) in front and a (negative) pair of lenses at the back, acting as a teleconverter and "field flattener". Of course this is a simplified explanation.

I) If we make the triplet with f=300mm and a aperture of f5.6, the lens will be roughly 300mm long, and the triplet alone is sufficient - no need for a negative element in the back. The Noflexar 5.6/400mm has this construction, for example.

II) If we make a triplet with f=200mm (to make the overall lens shorter, about 200mm) we will need a negative lens group in the back, acting as an 1.5x teleconverter. The triplet type "200mm" master lens in front no needs to have an aperture of f3.73 (=f5.6/1.5).

III) If we want to have a really short 300mm lens (about 150mm long), we have to make the master triplet f=150mm, with an aperture of f2.8. Of course, to get the desired 5.6/300mm lens, we need in addition a rear group acting as a 2x teleconverter.



Let's look at a real life example:

"Lens I" is the Minolta Tele Rokkor 4.5/300mm (the SR type lens, not the later MC 4.5/300m!!). The lens was released in 1965, and certainly has no ED/AD/ULD glass (v=80), probably not even LD glass (v=70). It has a triplet type master lens and a sligtly negative single lens in the back, acting as a field flattener. Its overall length (first lens to sensor) is quite exactly 30 cm.

"Lens II", the SMC Pentax-M* 4/300mm, is a highly sophisticated and extremely compact 300mm lens (132mm long, which means the distance from firts lens to sensor is about 17cm). It was released around 1980, and it uses the best glass available: Three (!) large ED lenses (v=81.4), and a glass resembling the "Leizt Noctilux glass" in the rear part of the lens (nD_1.88, v=41).

Here they are:


Now let's look at their chromatic correction. You would assume the Pentax M* 4/300mm, having three large ED lenses, to have little lateral CAs? So I did ... and I was dead wrong (100% cormer crops from the 24 MP A7II, as usual):


Here comes the Minolta SR 4.5/300mm - physically long lens, no ED glass, probably no LD glass, simple construction, 15 years older ... but quite exactly twice as long as the Pentax:


It has less CAs than the Pentax ...

visualopsins wrote:
Optical materials and techniques such as apo and aspherical also contribute or lessen length imho.

APO lenses are based on ED/AD/ULD glass (v=80), Super ED glass (v=90) or crystalline fluorite (v=95). All these materials have a low refractive index, causing lens systems to be longer compared to "normal" glass.

Aspherical lenses are hardly ever used in long tele lenses.

Stephan


PostPosted: Fri Aug 09, 2019 8:53 pm    Post subject: Reply with quote

Got to admit I've been stunned by the CZJ 50. The colours are so rich and great contrast. Feels almost like velvia in some ways.

This is unprocessed:



Somy a6000, iso 100, I think around f5.6

Few more shots and full sizes her3;
https://flic.kr/s/aHsmFYiBZK

Seems like a lot of bang for the buck tbh..


PostPosted: Fri Aug 09, 2019 9:37 pm    Post subject: Reply with quote

stevemark to my eyes there is color shift between Pentax & Minolta CA examples, with Pentax exhibiting more purple fringing less green, Minolta more teal fringing less lighter purple. (due to slight focus difference?) Pentax CA colors appear more saturated than Minolta, appear like more CA but in fact both lenses are about the same to me. Am I missing something obvious?

Yes my comment about apo & aspherical was silly, thanks.


PostPosted: Fri Aug 09, 2019 10:28 pm    Post subject: Reply with quote

visualopsins wrote:

...
Am I missing something obvious?


My point was that Pentax with its M* 4/300mm (in spite of using three large ED lenses and expensive Noctilux glass) could not reach the color correction of the "ancient" and very simply Minolta design. Why? Pentax put too much emphasis on making an extremely small 4/300mm lens (measuring only 132mm).

Stephan


PostPosted: Sat Aug 10, 2019 12:08 am    Post subject: Reply with quote

stevemark wrote:
visualopsins wrote:

...
Am I missing something obvious?


My point was that Pentax with its M* 4/300mm (in spite of using three large ED lenses and expensive Noctilux glass) could not reach the color correction of the "ancient" and very simply Minolta design. Why? Pentax put too much emphasis on making an extremely small 4/300mm lens (measuring only 132mm).

Stephan


My point is that Pentax reached the color correction but did not improve on Minolta's. The steeper angles weren't limiting corrections.


PostPosted: Sat Aug 10, 2019 4:56 am    Post subject: Reply with quote

Left a footprint on the 100th page!

Vivitar series 1, 135mm f/2.3
Vivitar 135mm f/2.8 Close Focusing
Minolta auto tele Rokkor 100mm f/3.5, looking forward to seeing how this one performs.


PostPosted: Sat Aug 10, 2019 4:13 pm    Post subject: Reply with quote

To complement and compare with the komine made viv close focus 28mm f2 I already have. Seller described this as "iris clean and snappy" but he was telling fibs, however my winning bid was still a good price for a PKA. Looks like there's quite a bit of online info re disassembly and cleaning, not a difficult job.



PostPosted: Sat Aug 10, 2019 5:08 pm    Post subject: Reply with quote

marcusBMG wrote:
To complement and compare with the komine made viv close focus 28mm f2 I already have. Seller described this as "iris clean and snappy" but he was telling fibs, however my winning bid was still a good price for a PKA. Looks like there's quite a bit of online info re disassembly and cleaning, not a difficult job.

This is a good lens optically, not as bad as in some other reviews. Saturated color as Kiron's character. Mine came in just fine with the aperture. But I am not sure if it will become stuck afterwards.


PostPosted: Sat Aug 10, 2019 9:40 pm    Post subject: Reply with quote

vivaldibow wrote:
marcusBMG wrote:
To complement and compare with the komine made viv close focus 28mm f2 I already have. Seller described this as "iris clean and snappy" but he was telling fibs, however my winning bid was still a good price for a PKA. Looks like there's quite a bit of online info re disassembly and cleaning, not a difficult job.

This is a good lens optically, not as bad as in some other reviews. Saturated color as Kiron's character. Mine came in just fine with the aperture. But I am not sure if it will become stuck afterwards.


I agree completely with this.
The colour rendition is its greatest strength.
Softer than others - mine was - but with a character of its own.
Oily blades seem to haunt the Kiron Kinos though.
Tom


PostPosted: Sun Aug 11, 2019 12:58 am    Post subject: Reply with quote



...and it came with the hard-to-come-by cone hood. It was this lens or the Nikkor 45/2.8. From what I have read, believe I made the better choice. Version 2 is unattractive while V.3 is even more attractive but a lot larger.


PostPosted: Tue Aug 13, 2019 3:25 pm    Post subject: Reply with quote



New cam and new lens - a classic mechanical combination in top condition:
Leica R6 from the first 4000 pcs production batch from 1987 and the Summicron-R 2.0/50mm from 1978.
A R-winder is still on the way to me.


PostPosted: Thu Aug 15, 2019 12:36 pm    Post subject: Reply with quote



Now lets see what this can do.


PostPosted: Thu Aug 15, 2019 5:59 pm    Post subject: Reply with quote

My latest lens is total junk. I was excited to add another Minolta lens to my collection.
Minolta. MD tele Rokkor X 135mm f2.8, this is the second MDii version that was shorter and lighter.
Unfortunately it has heavy haze to the second optic group, and heavy scratching to the rear element. In other words it's junk.

Looks like this lens comes completely apart with no glued elements, so the haze should be removable. Still would have the scratched rear element, but might be usable.


Last edited by walter g on Fri Aug 16, 2019 7:41 am; edited 1 time in total


PostPosted: Thu Aug 15, 2019 9:39 pm    Post subject: Reply with quote

When East meets West meets East...





Laugh 1

It also came with a Tamron-f 135/2.8 which has a touch of fungus on it.. Sad


and a really nice early zebra Pentacon 50mm f/1.8, i.e an Oreston in all but name.. a keeper as I figure I can offload my M42 Oreston then.. D

So as for the Cavalier, given the badge on the bottom I presume it's a Pentax, anyone got any ideas as to which? It's optically in good condition but the aperture won't budge beyond f.8.. :/


PostPosted: Fri Aug 16, 2019 9:29 am    Post subject: Reply with quote

Gott23 wrote:
So as for the Cavalier, given the badge on the bottom I presume it's a Pentax, anyone got any ideas as to which? It's optically in good condition but the aperture won't budge beyond f.8.. :/


Afaik, Pentax didn't manufacture lenses for anyone else, it certainly doesn't look like a Pentax.
The Pentax label probably refers to the lens mount, Pentax screw.


PostPosted: Sat Aug 17, 2019 7:08 am    Post subject: Reply with quote

DigiChromeEd wrote:
Gott23 wrote:
So as for the Cavalier, given the badge on the bottom I presume it's a Pentax, anyone got any ideas as to which? It's optically in good condition but the aperture won't budge beyond f.8.. :/


Afaik, Pentax didn't manufacture lenses for anyone else, it certainly doesn't look like a Pentax.
The Pentax label probably refers to the lens mount, Pentax screw.
I learn something new every day.. Very Happy

Seriously, so in a cynical ploy they badge the lens with a pentax sticker, and it also had pentax front and rear caps.. Very Happy

As for the lens, I have had a rummage on the net and I have found it in another guise, namely as the Prinzflex Auto Reflex 28mm



I reckon my copy is a bit battered as the focus on it is totally off, near focus fine buy anything beyond six foot/2m is impossibly soft/out of focus.. that and the aperture not closing beyond f/5.6..